The present application relates generally to power systems and, more particularly, to a plasma generation device assembly, an arc mitigation device, and a method of assembling the plasma generation device assembly.
Known electric power circuits and switchgear generally have conductors that are separated by insulation, such as air, or gas or solid dielectrics. However, if the conductors are positioned too closely together, or if a voltage between the conductors exceeds the insulative properties of the insulation between the conductors, an arc can occur. The insulation between the conductors can become ionized, which makes the insulation conductive and enables arc formation. In addition, arcs may occur as a result of degradation of the insulation due to age, damage to the insulation from rodents, and/or improper maintenance procedures.
An arc flash causes a rapid release of energy due to a fault between phase conductors, between a phase conductor and a neutral conductor, or between a phase conductor and a ground point. Arc flash temperatures can reach or exceed 20,000° C., which can vaporize the conductors and adjacent equipment panels. In addition, an arc flash or fault is associated with a release of a significant amount of energy in the form of heat, intense light, pressure waves, and/or sound waves, which can cause severe damage to the conductors and adjacent equipment.
In general, the fault current and the energy associated with an arc flash event are lower than a fault current and energy associated with a short circuit fault. Due to an inherent delay between closure of a relay and a circuit breaker clearing an arc fault, a significant amount of damage may occur at the location of the fault.
At least some known systems use an arc mitigation system to divert arc energy from the location of the arc flash or fault. The arc mitigation system has an arc containment device which often includes a plasma generation device that emits ablative plasma towards electrodes within the arc containment device or live terminals that terminate inside the containment device when the arc flash event is detected. The ablative plasma reduces or brakes a dielectric strength of the medium, or insulation, between the electrodes, and the medium breaks down such that an electrical arc is formed between the electrodes. The electrical arc diverts energy from the arc flash location until the source of the energy is abated or disconnected.
At least some known plasma generation devices are positioned within base structures or pedestals that position the plasma generation devices at a desired distance from the electrodes. As a result of the generation of the ablative plasma and the formation of the electrical arc between the electrodes, high pressure and/or high temperature gases are formed within the arc containment device. The high pressure and/or high temperature gases may at least partially escape the arc containment device through the plasma generation device and the pedestal, thus causing movement or displacement of the arc containment device and causing stress to one or more fastening components of the arc containment device. Such movement and/or stress may also cause damage to the plasma generation device, to the pedestal, and/or to other components of the arc containment device.